The statements you've provided seem generally acceptable and convey positive qualities associated with success and greatness. However, the popularity of specific phrases or expressions can vary, and the number of search results on Google may not always be a reliable indicator of naturalness or correctness. In terms of language, these statements are grammatically correct and make logical sense. They convey the idea that both great and successful people often possess positive mindsets and attitudes. The lack of a large number of search results doesn't necessarily imply that the statements are unnatural or incorrect; it could be due to various factors, including the specific phrasing or the use of common language. If you're concerned about naturalness, you might consider rephrasing or using alternative expressions to convey similar ideas. For example: Great individuals often have positive mindsets. Exceptional people typically exhibit positive attitudes. Success is often linked to a positive mindset. Successful individuals often demonstrate positive attitudes. These alternatives maintain the core ideas while using slightly different language. Keep in mind that language preferences can vary, and different phrasings may resonate more with different audiences.

All four are correct.